An internal combustion engine combusts an air/fuel mixture within cylinders to produce drive torque. An engine control module controls the amount of fuel injected into the cylinders to control the air/fuel mixture, and in turn control the drive torque. Additionally, the engine control module may control spark timing to control the drive torque.
For example, the engine control module may retard spark timing in order to decrease drive torque. However, spark timing that is too far retarded may cause a misfire. Hydrocarbons released during a misfire may combust within a catalyst of an exhaust system, which may cause damage to the catalyst. Furthermore, the released hydrocarbons may increase a level of hydrocarbon emissions from the exhaust system.